Leonard: See, this is the good thing about having a girlfriend 9,000 miles away. I can spend my nights doing whatever I want.
Howard: You mean like playing nerd games with us and then taking a suspiciously long shower?
Leonard: Maybe.

Leonard: Penny, as a scientist, my job is to figure out why things happen. But I don't think I'll ever understand how someone like me could get to be with someone like you. You know maybe I don't need to understand it, I just need to be grateful. I love you, Penny.

Leonard: What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?
Sheldon: Screwed?
Leonard: There you go.

Leonard: My point is, while you're spending all this time on your own, building computers or practicing your cello, what you're really doing is becoming interesting. When people finally do notice you, they're gonna find someone a lot cooler than they thought. And for those of you that were popular in high school, it's over, sorry. Thank you. Congratulations.

Penny: (Whispers) Here she comes.
Howard: Smart. Whisper so the deaf chick doesn't hear you!

Sheldon: The entrance to the dungeon is a moss covered door. You manage to open it only to find yourself face-to-face with a hideous, foul-smelling, moss-covered ogre. What do you do?
Howard: I say, "Hey Ma, what's for dinner?"

Raj: I don't know if I wanna play any more.
Sheldon: Because you don't have a girlfriend? Well, good lord, if that becomes a reason to not play dungeons and dragons, this game is in serious trouble.